yes you will be able to update after installation just check for updates and install. I it this way so the installation goes faster, then after install I can update and install the Restricted extras and ect. That way I can use the computer and let the updates install
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TrailRiderJul 6 '12 at 21:37

As an alternative to Keryx, you can use apt-offline or apt-offline-gui.Pre-requistes: A friend's system with Internet connection. apt-offline installed in both your systems.

The Offline installation is achieved in 3 simple steps.

Step 1:
Generate a signature file on the Disconnected Debian box at homeapt-offline set /tmp/apt-offline.sig
The above command will generate all information required from apt about updating its database.

Step 2:
Download data based on the signature file generated earlierapt-offline get C:\apt-offline.sig --threads 5
The above command will download data as mentioned in the signature file. To speed up downloads (that can be from multiple apt repositories), in this example we spawn 5 download threads.
Once completed, you could just copy the data (an archive file, if you used the --bundle option) back to the removable medium and copy it back onto your offline host.

Step 3:
Once you're back upon the home Debian machine, you feed the data from the removable medium to apt-offline:apt-offline install /media/USB/apt-offline.zip
This will update the APT database on your disconnected machine seamlessly.

Apt-offline can be even used in Windows systems. In my opinion, apt-offline is the best option for Offline installation.

If you have already burned your ubuntu release at a USB or a CD common sense states that all the files and components of your operating system are included. That happens to any operating system.

Take for instance Windows:

-Are you in need of an internet connection when you install it at a computer through a CD?

-No.

On the other hand if you are going to install using the windows installer (Wubi) which installs ubuntu at your existing Windows partition, you must have an internet connection in order to download the .iso and proceed to the installation.

However you should notice that if you do not have a working connection you will not be able to download any updates(except if you have an old release which is no longer supported by Canonical) from the update manager. You can always type sudo apt-get update in order to install any updates and fixes to your system.